Picturing the changing feathering of the starlings

The starlings undergo a complete molt every year. Their plumage also changes again and again throughout the year.

A starling’s year revolves around a single fixed period: the breeding season (May and June). Once this strenuous time is over and the chicks have safely left the nest, the adult birds get some time to renew their plumage. In other words, the molt begins. The worn feathers of an entire year are completely renewed. The new feathers are dark with a white tip and look the same in males and females. Those white tips result in the starling’s early winter feathering: dark with white dots.

Now the mysterious part begins! The bird loses more and more white dots over the year! Shortly before the mating season, the starling gets a completely dark plumage with green or violet glimmer. How is that possible?

The answer is simple: the wear. After all, one cannot run around the countryside for a year in a shimmering ball gown without dirtying the dress. The birds move, rub against trees and shrubs, and are exposed to wind and weather. As a result, the white tips of the feathers are gradually worn out. Once almost all the white dots are gone, the "real" plumage with its green or violet tint is much more apparent. The sunlight can make it brighter when it is not scattered by the white dots.

The breeding season begins at this stage of the year. Once it's over, the molt starts again and the cycle goes on.

The starling’s beak also undergoes some changes throughout the year. The nearer the breeding season, the more sex hormones the starling produces. This ensures that the beak goes from black in winter to yellow-white during mating time. This color change also helps distinguish males from females. The male gets a bluish spot at the base of the beak while the female gets a reddish one.